Message ID | 20200831040333.6058-13-khalid.elmously@canonical.com |
---|---|
State | New |
Headers | show |
Series | Requested eBPF improvements | expand |
On 31.08.20 06:03, Khalid Elmously wrote: > From: Joe Stringer <joe@wand.net.nz> This patch is missing: BugLink: https://bugs.launchpad.net/bugs/1887740 > > [ upstream commit 7ae215d23c12a939005f35d1848ca55b6109b9c0 ] > > Avoid taking a reference on listen sockets by checking the socket type > in the sk_assign and in the corresponding skb_steal_sock() code in the > the transport layer, and by ensuring that the prefetch free (sock_pfree) > function uses the same logic to check whether the socket is refcounted. > > Suggested-by: Martin KaFai Lau <kafai@fb.com> > Signed-off-by: Joe Stringer <joe@wand.net.nz> > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > Acked-by: Martin KaFai Lau <kafai@fb.com> > Link: https://lore.kernel.org/bpf/20200329225342.16317-4-joe@wand.net.nz > Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> > Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> > --- > include/net/sock.h | 25 +++++++++++++++++-------- > net/core/filter.c | 6 +++--- > net/core/sock.c | 3 ++- > 3 files changed, 22 insertions(+), 12 deletions(-) > > diff --git a/include/net/sock.h b/include/net/sock.h > index 6cb1f0efa01b..e13e9b7c34d1 100644 > --- a/include/net/sock.h > +++ b/include/net/sock.h > @@ -2492,6 +2492,21 @@ skb_sk_is_prefetched(struct sk_buff *skb) > #endif /* CONFIG_INET */ > } > > +/* This helper checks if a socket is a full socket, > + * ie _not_ a timewait or request socket. > + */ > +static inline bool sk_fullsock(const struct sock *sk) > +{ > + return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); > +} > + > +static inline bool > +sk_is_refcounted(struct sock *sk) > +{ > + /* Only full sockets have sk->sk_flags. */ > + return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE); > +} > + > /** > * skb_steal_sock > * @skb to steal the socket from > @@ -2504,6 +2519,8 @@ skb_steal_sock(struct sk_buff *skb, bool *refcounted) > struct sock *sk = skb->sk; > > *refcounted = true; > + if (skb_sk_is_prefetched(skb)) > + *refcounted = sk_is_refcounted(sk); > skb->destructor = NULL; > skb->sk = NULL; > return sk; > @@ -2512,14 +2529,6 @@ skb_steal_sock(struct sk_buff *skb, bool *refcounted) > return NULL; > } > > -/* This helper checks if a socket is a full socket, > - * ie _not_ a timewait or request socket. > - */ > -static inline bool sk_fullsock(const struct sock *sk) > -{ > - return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); > -} > - > /* Checks if this SKB belongs to an HW offloaded socket > * and whether any SW fallbacks are required based on dev. > * Check decrypted mark in case skb_orphan() cleared socket. > diff --git a/net/core/filter.c b/net/core/filter.c > index 4033799dafd5..baaeab75327c 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -5468,8 +5468,7 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = { > > BPF_CALL_1(bpf_sk_release, struct sock *, sk) > { > - /* Only full sockets have sk->sk_flags. */ > - if (!sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE)) > + if (sk_is_refcounted(sk)) > sock_gen_put(sk); > return 0; > } > @@ -5995,7 +5994,8 @@ BPF_CALL_3(bpf_sk_assign, struct sk_buff *, skb, struct sock *, sk, u64, flags) > return -ENETUNREACH; > if (unlikely(sk->sk_reuseport)) > return -ESOCKTNOSUPPORT; > - if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) > + if (sk_is_refcounted(sk) && > + unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) > return -ENOENT; > > skb_orphan(skb); > diff --git a/net/core/sock.c b/net/core/sock.c > index 036ba43d044a..bcb7affcc1e0 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -2071,7 +2071,8 @@ EXPORT_SYMBOL(sock_efree); > #ifdef CONFIG_INET > void sock_pfree(struct sk_buff *skb) > { > - sock_gen_put(skb->sk); > + if (sk_is_refcounted(skb->sk)) > + sock_gen_put(skb->sk); > } > EXPORT_SYMBOL(sock_pfree); > #endif /* CONFIG_INET */ >
diff --git a/include/net/sock.h b/include/net/sock.h index 6cb1f0efa01b..e13e9b7c34d1 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2492,6 +2492,21 @@ skb_sk_is_prefetched(struct sk_buff *skb) #endif /* CONFIG_INET */ } +/* This helper checks if a socket is a full socket, + * ie _not_ a timewait or request socket. + */ +static inline bool sk_fullsock(const struct sock *sk) +{ + return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); +} + +static inline bool +sk_is_refcounted(struct sock *sk) +{ + /* Only full sockets have sk->sk_flags. */ + return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE); +} + /** * skb_steal_sock * @skb to steal the socket from @@ -2504,6 +2519,8 @@ skb_steal_sock(struct sk_buff *skb, bool *refcounted) struct sock *sk = skb->sk; *refcounted = true; + if (skb_sk_is_prefetched(skb)) + *refcounted = sk_is_refcounted(sk); skb->destructor = NULL; skb->sk = NULL; return sk; @@ -2512,14 +2529,6 @@ skb_steal_sock(struct sk_buff *skb, bool *refcounted) return NULL; } -/* This helper checks if a socket is a full socket, - * ie _not_ a timewait or request socket. - */ -static inline bool sk_fullsock(const struct sock *sk) -{ - return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); -} - /* Checks if this SKB belongs to an HW offloaded socket * and whether any SW fallbacks are required based on dev. * Check decrypted mark in case skb_orphan() cleared socket. diff --git a/net/core/filter.c b/net/core/filter.c index 4033799dafd5..baaeab75327c 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5468,8 +5468,7 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = { BPF_CALL_1(bpf_sk_release, struct sock *, sk) { - /* Only full sockets have sk->sk_flags. */ - if (!sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE)) + if (sk_is_refcounted(sk)) sock_gen_put(sk); return 0; } @@ -5995,7 +5994,8 @@ BPF_CALL_3(bpf_sk_assign, struct sk_buff *, skb, struct sock *, sk, u64, flags) return -ENETUNREACH; if (unlikely(sk->sk_reuseport)) return -ESOCKTNOSUPPORT; - if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) + if (sk_is_refcounted(sk) && + unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) return -ENOENT; skb_orphan(skb); diff --git a/net/core/sock.c b/net/core/sock.c index 036ba43d044a..bcb7affcc1e0 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2071,7 +2071,8 @@ EXPORT_SYMBOL(sock_efree); #ifdef CONFIG_INET void sock_pfree(struct sk_buff *skb) { - sock_gen_put(skb->sk); + if (sk_is_refcounted(skb->sk)) + sock_gen_put(skb->sk); } EXPORT_SYMBOL(sock_pfree); #endif /* CONFIG_INET */